Yup, I'm going to chime in with the rest of the guys and say it does. It's been a while since I was last in Japan, but I definitely got there via the Yamanote. It's one stop after Kanda, no?
You are of course entitled to your opinion and maybe that wouldn't suit you. However, I have my 3DS in front of me righ now and when I hold it like that, it feels absolutely fine for me.
I have a great headset that I like to use and I don't want to have to buy a new headset. There would be no reason that it couldn't be a multi-functional headphone port with a mic port for both types of headset.
I think the dpad on the current 3DS is fine were it is, at the bottom-left, so I don't see any problems swapping the dpad and nub over, and having a second on the right. Also, as previously stated, this would probably be better as an XL version, although, even the current 3DS is good for me regarding size and placement.
Again, this was just for fun and was actually made before the 3DS was released. So I had no idea about the actual size of the thing.
I find the DS a great size for my hands and I use the d-pad in it's current location fine. The size is meant to be bigger overall (look at the hdmi port). I suppose I should have called it the 3DSiXL.
Still, at the end of the day, I'm not a product designer and the above illustration is for shits and giggles. There is no need to take the illustration so seriously bud. :)
This reminds me of Terragen. It's a free landscape generator. I've learned about it quite a few years ago, and I still have no idea what I am doing with it. You can get it from [www.planetside.co.uk]